Method of controlling blast furnaces



Y June9, 1931. J. F. AUSTIN OCETAL METHOD OF CONTROLLING BLAST FURNACES 3 Sheets-Sheet 1 Original Filed Aug. 30, 1927 FIG. I.

June 9, 1931. .1. F. AUSTIN ET AL METHOD OF CONTROLLING BLAST FURNACES .Original Filed Aug. 50, 1927 3 Sheets-Sheet .2

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avwe ntoz June 9, 1931. J. F. AUSTIN ET AL 1,809,326

METHOD OF CONTROLLING BLAST FURNACES 3 Sheets-Sheet 3 Original Filed Aug. 30, 1927 FIGS Patented June 9, 1931 UNITED STATES PATENT OFFICE JOHN F. AUSTIN, 0F MURRAY, AND DONALD E. MOINTOSH, OF SALT LAKE CITY, UTAH, ASSIGNORS 'I'O AMERICAN SMELT'ING & BEFINING COMPANY, OF NEW YORK; N. Y.,

A'CORPORATION OF NEW JERSEY METHOD OF CONTROLLING BLAST FURNACES Original application filed August 30, 1927, Serial No. 216.352. Divided and this application illed'December 20, 1928. Serial No. 327,287.

blast or both in accordance with the state of the furnace as indicated from the samples. According to the invention the sampling oint'or zone is that point or zone in the urnace which is most sensitive to changes in the condition of the furnace. and is located in the charge somewhere between the tuyeres and the flue.

The apparatus for carrying out the invention may comprise a suitable sampling tube which is inserted preferably through the top of the furnace to communicate with the critical zone. may be provided to keep the tube from burning out due to the intense heat of the furnace. The sampling tube may have connected therewith suitable gas analyzin apparatus for analyzing the sample 0 gas and also a suitable source of compressed air for blowing out thetube at frequent intervals. A suitable'p'lunger passing through the sampling tube may also be provided to prevent the sampling tube from clogging up. The tube may be made to operate as an auxiliary tuyere if desired. Furthermore,

suitable apparatus may be connected to the sampling tube so that the porosity of the charge may be measured from time to time.

Various other features and advantages of the invention will be apparent from the following particular description and from an inspection of the accompanying drawin s.

Although the novel features which are elieved to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, the mode of its operation and the manner of its organization may be better understood by referring to the following description taken in con- Suitable cooling means nection with the accompanying drawings forming a part thereof, in which Fig. 1 is a section of awell known type of blast furnace equipped to practice the invention;

Fig. 2 is an elevation partly in section of zhe sampling tube and associated apparaclaims parts will be identified by specific names for convenience, but they are intended Fig. 3 is a top planview of the sampling to be as generic in their application to similar parts as the art will permit.

Like reference characters denote like parts in the several figures of the drawings.

Referring now to the drawings, and more particularly to Fig. 1, a conventional type of.

last furnace is illustrated with which the invention may be practiced. This furnace, which may be of the type used for smelting lead ores, may comprise the usual shaft 1 supported by a plurality of pillars 2. The shaft may be provided with a flue opening 3 and witha fire brick lining 4. Located between the pillars is the base or crucible 5- of the furnace, and extending between the base and the shaft lining is a water jacket 6, suitable being supplied with an air blast in any desired manner.

Suitable I-beams 8 for supporting the roof 9 are provided at the top of the furnace, the roof having'the usual opening 10 through Arranged around which the charge is fed. Disposed across the opening is an inverted channel iron 11. Disposed within the furnace and below the charge opening is a spreader 12 which is used for distributing the charge in a manner well known in the art.

The detailed construction of the furnace forms no part of the present invention except in association with the sampling tube 13. The invention may be practiced with any kind of metallurgical furnace and is not limited to the particular furnace shown. The furnace may be charged and operated inany ap roved manner known in the art.

eferring now more particularly to Figs. 2 and 3, the sampling tube 13 may comprise an outer casing or jacket 14 having a cylindrical side wall 15 and end walls 16 welded there in. Disposed within the outer casing 14 is an inner tube 17 passing through both upper and lower end walls, and secured therein. Located within the outercasihg 14 and at 'the bottom is a ring of fire brick 18 which is suitably held therein by means of set screws 21 until it is fused in position by the heat of the furnace.

Also connected to the outer casing 14 is a pair of water cooling pipes, the intake pipe 22 being extended through the upper end wall 16 to almost the bottom of the casing, and the outlet pipe 23 being extended mere- 1y through the upper wall 16.

Connected to the inner tube 17 is a T-fitting 24, the lower end of the fitting being screwed on to the inner tube and the upper end being provided with a disc25 having an openin through which extends a plunger rod 26 having an eye 27 at its upper end. A packing 28 is arranged in the upper end of the T-fitting, and a gland 29 is threaded into the fitting to compress the packing against the plunger rod to make a tight joint.

A connecting pipe 30 is led off from the side I of the fitting as shown.

Just below the top of the casing 14 a collar 31 is provided, the collar being made up of two halves suitably clamped together and provided with holes through which links 34' are threaded (see Fig. 1), the links extending up through the spreader 12 and being affixed to the channel iron 11 as shown.

Referring'now more particularly to Fig. 4, the inlet pipe 2 2 for the cooling water is provided with a'valve 35 as shown, the outlet ipe 23 being shown as led away from the urnace. The connecting pipe 30 leading away from the furnace is shown as dividing into two branches 36 and 37, each branch being provided with a valve 38 and 39. Branch 36 isconnected to a supplyof compressed air and has a pressure gage connected thereto on the furnace side of valve 38. Branch 37 is connected to the gas analyzing apparatus which may be of the recording, graphic type or any other well known type. ,7 Mounted within the channel 11 and directly over the plunger rod 26 is a ulley 40 over which passes a cable 43- exten ing from the plunger rod, the cable extending along the channel to'a pulley 44 by which the directhe cable then extending to a pulley 45, and thence to an operating arm 46.

Mounted at the side of the furnace is a support 47 having a bell crank lever 48 mounted therein and also 'a cam 49 in the form of a Wheel having a notch 50. One end of the lever 48 comprises the operating arm 46, and the other end is provided with a roller 51 which cooperates with the cam. As the cam rotates in the direction of the arrow in Fig. 6, it will be seen that the operating arm 46 will alternately pull the-cable 43 and suddenly release it, the movement of the cable being communicated to the plunger rod to keep the inner tube clear l of soot and solid particles. The plunger rod is provided with a cross bar 52 (see Fig. 5) from which suitable weights 53 are suspended to aid the plunger rod in its downward movement.

In order to practice theinvention using the apparatus illustrated, the. sampling tube 13 is inserted in the furnac e in the manner shown in Fig. 1, the lower-end being in thecharge at the critical or sehsitive zone. The cooling water willbe circulatedan'd the valve 38 will be closed while the valve 39 will be open. The plunger actuating mechanism will be Working and samples of the furnace gases may pass out of the branch 37 into suitable analyzing apparatus indicated diation of the cable is changed at right angles,

The best and most critical zone is found can have comparatively long life, always operating satisfactorily.

The method according to the. invention gives the accurate condition of the furnace at all times, andsince the furnace is adjusted in accordance with each analysis, the efficiency of the furnace is greatly inc.eased. Furthermore, the cooling action of the tube in the furnace holds the reduction zone low, thus decreasing the tendency for blow holes to occur, and thereby making for '39 is closed, and the valve 38'fis opened to blow out the dirt accumulations, this also-- having abeneficial efiecton the running of the furnace. may be. used to measure'tlle porosity of any given charge by noting on the-pressure gage the pressure of the blast necessary to blow air through the charge after blowing out the tube Thus a method and apparatus has been disclosed by which a'blast furnace may be 1 taken.

controlled in a simple and efficient manner to give improved results. Samples of gas can be taken as frequently as desired from the selected critical zone and the gas can be analyzed very quickly. The furnacemay then be adjusted as indicated by the samples Thus a furnace can be run at all times at a maximum rateof efficiency, resulting not only in a saving of fuel but in an improved smelting action. The; use of the sampling tube as anauxiliary tuyere also gives beneficial results and its use to measure porosity of the charge is also of advantage. The apparatus is built ruggedly to withstand the severe operating conditions. The sampling tube will not readily burn out or clog up andwill give long and efficient service.

This application is a division of application, Serial No. 216,352,-filed August 30, 1927.

Although certain novel features of the invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the several steps of the process and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. The method of controllin the operation of a metallurgical furnace w ich comprises withdrawing a sample of gas from a sensitive zone within the charge and then adjusting the materials fed to said furnace in accordance with said sample.

2. The method of controlling the operation of a furnace which comprises withdrawing a sample of gas from a sensitive zone within the charge and then adjusting the materials fed to said furnace in accordance with said tive fuel and air in accordance with said samle. a

4. The method of operating a blast furnace which comprises withdrawing samples of gas from a point wlthin the charge at intervals In addition the sampling tube' of samples.

and then adjusting the materials fed to said furnace in accordance with the samples taken.

5 The method of operating a blast furnace of the shaft type which comprises withdrawing samples 0 gas from a zone within the charge, which is most sensitive to variations in the materials fed to said furnace, at frequent'intervals and then adjusting the materials fed to the blast furnace from the results 6. The method of operating a blast furnace of the shaft type which comprises withdrawing samples of the contents of the'furnace from a zone within the charge, which is most sensitive to Variations in the materials fed to said furnace, at frequent intervals and then adjusting the materials fed to the blast furnace from the results of the samples.

7. The method of operating a furnace which comprises withdrawing samples of the contents of. the furnace from a point within the charge at'frequent intervals, analyzing the samples and then adj ustingthe materials fed to the furnace from the results of the analyses.

8. The method of operating a furnace hav-' contents of the furnace through said sampling device for information in operating the furnace and then forcing air lnto said furnace through said sampling device when not withdrawing samples to keep the device clean and to cause said .device to act as an auxiliary tuyere.

In testimony whereof we have hereunto set our hands.

JOHN F. AUSTIN.

DONALD H. MoINTOSH. 

